1. Field of the Invention
The present invention relates to an improved breakaway standard support assembly and to a unique coupler for use in the same.
2. Description of the Prior Art
Numerous serious and fatal vehicle accidents have been caused as a result of vehicles colliding with unyielding road sign standards, light standards and the like.
It has previously been suggested to provide the support structures for such standards with an element which will fracture upon the application of horizontal impact as by a vehicle hitting the standard support at a certain force level. See, generally, U.S. Pat. Nos. 3,355,988; 3,521,413; and U.S. Pat. No. 3,637,244.
It has also been suggested to couple a standard to a base in such a manner that a horizontally imposed impact force will cause separation of the parts without requiring fracture. See. U.S. Pat. No. 3,552,698. U.S. Pat. No. 3,630,474 discloses the use of a plurality of coupler members which have two doors each threaded to receive anchoring or standard securing bolts.
U.S. Pat. Nos. 4,007,564 and 4,052,826 disclose various embodiments of coupler members which have longitudinal grooves which are adapted to fracture upon the application of horizontal impact. The latter patent also discloses a washer which applies additional local forces which are said to facilitate such fracture.
In spite of these disclosures there remains a very real and substantial need for an improved breakaway standard support assembly.